A variant circulating in New York City may weaken the effectiveness of various vaccines. Although the city has vaccinated about 1 million people, nonwhite people have received doses at lower rates.

■ The rates of Covid-19 infection across Europe have been cut in half from the winter peak, the World Health Organization said on Thursday.

■ European leaders are calling for a “vaccine passport” in advance of the summer tourism season.

■ Two more Chinese vaccine makers said their vaccines had effectively prevented serious illness, which could help speed up the country’s inoculation drive.

■ Moderna said it would test vaccines modified to protect against a variant first discovered in South Africa.
The New York Times